Add a contributing guide

CONTRIBUTING.md

@@ -0,0 +1,107 @@
+## Accept Developer Certificate of Origin
+
+In order for your contributions to be accepted, you must [sign off](https://git-scm.com/docs/git-commit#git-commit---signoff) your Git commits to indicate that you agree to the terms of [Developer Certificate of Origin](https://developercertificate.org/).
+
+## Follow the Code of Conduct
+
+In order to foster a more inclusive community, Gradle has adopted the [Contributor Covenant](https://www.contributor-covenant.org/version/1/4/code-of-conduct/).
+
+Contributors must follow the Code of Conduct outlined at [https://gradle.org/conduct/](https://gradle.org/conduct/).
+
+## Making Changes
+
+### Development setup
+
+You can test local changes to `gradle-completion.bash` by executing 
+
+```bash
+source path/to/gradle-completion.bash
+``` 
+
+and then using completion as normal.
+
+For ZSH, set your `fpath` to point to the cloned git repository
+
+```bash
+export fpath=($HOME/src/your_user/gradle-completion \$fpath)
+```
+
+Then execute `unfunction _gradle && autoload -U _gradle` to reload the gradle completion function, after which you can try completion as normal.
+
+### Debugging
+
+You can get a debug trace of zsh completion by typing `Ctrl-X ?` instead of hitting `[TAB]`. That is especially helpful when submitting bug reports.
+
+Here's a handy [how-to on bash completion](https://iridakos.com/tutorials/2018/03/01/bash-programmable-completion-tutorial.html) and [zsh completion reference](https://github.com/zsh-users/zsh-completions/blob/master/zsh-completions-howto.org).
+
+## Updating Homebrew formula
+Updating the `gradle-completion` formula for Homebrew takes extra setup to perform all of the verification Homebrew requires.
+
+First you will need to ensure you can build native ruby gem extensions necessary for `brew audit`:
+
+``` 
+xcode-select --install
+brew vendor-install ruby
+
+# Check for any homebrew issues
+brew doctor
+
+# Add this to your environment
+export PATH="/usr/local/opt/ruby/bin:$PATH"
+export LDFLAGS="-L/usr/local/opt/ruby/lib"
+export CPPFLAGS="-I/usr/local/opt/ruby/include"
+export PKG_CONFIG_PATH="/usr/local/opt/ruby/lib/pkgconfig"
+```
+
+Ensure you have created a release tag on GitHub for `VERSION`.
+
+```
+export GRADLE_COMPLETION_VERSION="1.4.1"
+wget "https://github.com/gradle/gradle-completion/archive/v${GRADLE_COMPLETION_VERSION}.tar.gz"
+cat "vgradle-completion-${GRADLE_COMPLETION_VERSION}.tar.gz" | shasum -a 256 | awk '{print $1}'
+
+# Use brew tools to audit and create PR to homebrew/core
+brew bump-formula-pr --url=https://github.com/gradle/gradle-completion/archive/v<VERSION>.tar.gz --sha256=<SHA_256> gradle-completion
+```
+
+### Creating Commits And Writing Commit Messages
+
+The commit messages that accompany your code changes are an important piece of documentation, please follow these guidelines when writing commit messages:
+
+* Keep commits discrete: avoid including multiple unrelated changes in a single commit
+* Keep commits self-contained: avoid spreading a single change across multiple commits. A single commit should make sense in isolation
+* If your commit pertains to a GitHub issue, include (`Issue: #123`) in the commit message on a separate line
+* [Sign off](https://git-scm.com/docs/git-commit#git-commit---signoff) your commits to indicate that you agree to the terms of [Developer Certificate of Origin](https://developercertificate.org/).
+
+### Submitting Your Change
+
+After you submit your pull request, a Gradle core developer will review it. It is normal that this takes several iterations, so don't get discouraged by change requests. They ensure the high quality that we all enjoy.
+
+If you need to check on CI status as an external contributor, login as a guest.
+
+### Signing Off Commits After Submitting a Pull Request
+
+Pull requests are automatically verified that all commit messages contain the Signed-off-by line with an email address that matches the commit author. In case you didn't sign off your commits before creating a pull request, you can still fix that to confirm that you agree to the terms of [Developer Certificate of Origin](https://developercertificate.org/).
+
+To sign off a single commit:
+
+`git commit --amend --signoff`
+
+To sign off one or multiple commits:
+
+`git filter-branch --msg-filter "cat - && echo && echo 'Signed-off-by: Your Name <[email protected]>'" HEAD`
+
+Then force push your branch:
+
+`git push --force origin test-branch`
+
+## Getting Help
+
+If you run into any trouble, please reach out to us on the issue you are working on.
+
+## Our Thanks
+
+We deeply appreciate your effort toward improving Gradle. For any contribution, large or small, you will be immortalized in the release notes for the version you've contributed to.
+
+If you enjoyed this process, perhaps you should consider getting [paid to develop Gradle](https://gradle.com/careers)?
+

README.md

@@ -161,8 +161,9 @@ may be disabled. Enable it by adding the following to your `~/.zshrc` file:
 zstyle ':completion:*' use-cache on
 ```
 
-You can get a debug trace of zsh completion by typing `Ctrl-X ?` instead of hitting `[TAB]`. That is especially helpful
-when submitting bug reports.
+## Contributing
+
+See the [contributing guide](CONTRIBUTING.md).
 
 ## Acknowledgements
 Bash completion is inspired by [Nolan Lawson's Gradle tab completion for bash](https://gist.github.com/nolanlawson/8694399).
@@ -171,7 +172,7 @@ Zsh completion is an improved version of [zsh](https://github.com/zsh-users/zsh)
 
 Current improvements over built-in support:
  - Subproject tasks are completed
- - Gradle CLI options are current as of Gradle 4.1
+ - Gradle CLI options are current as of Gradle 5.2
  - Common Gradle properties are completed
  - Handles default build file as specified in settings.gradle
  - ~20x faster completion speed for medium to large projects